HSS cutting tips and turning tool making?

[mike s]

im looking to get some hss (or carbide) cutting tips for a homemade tool but everywhere i have looked they are around £10 each
does anyone know of a place i can get them cheaper?



for anyone with metalworking lathes, what tips do you use? every now and then i see the cutting block thingies (i know nothing about metal lathes) at a car boot sale and im considering picking one up cheap and take the tip off that....?

thanks

 

[Shay Vings]

I use Chronos. Min order £10. HSS blanks are square section max length 4 inch but a phone call may discover longer pieces?

 

[jasonB]

You could probably use a carbide inset from an indexable tool, the problem is they would need support near teh edge so you may get clearance problems when used fopr boring. The tips can be picked up on e-bay for about £1 each. The chronos site will show some indexable tooling, look at the Glanze section.

Another option if you want a scraper profile would be to grind up an old HSS planer knife.


Or as Shay says round and square HSS tool blanks are cheap enough for making tools like this

Jason

 

[CHJ]

As everyone else I would go to Chronos. or maybe one of the other suppliers on my list

I always pick up a selection whenever I visit a model engineering show, postage costs saved cover show entry. Another place I've picked them up is at Penny Farthing Tools in Salisbury, maybe a copper or two dearer but still in single figures.

 

[mike s]

thanks
i want to make a tool similar to the easy hollower http://www.woodcraft.com/Product/208021 ... wer-5.aspx
i will make the body of the tool with nothing-special-steel and i will tip it with these tips maybe?
http://cgi.ebay.co.uk/SPARE-TIPS-INDEXA ... 3a51f60951

they are only small so will only take small cuts but thats fine, i dont rush when turning anyway

does that sound ok?


thanks jason for telling me what to search on ebay
just the thing i was after and a good price also
no round ones though :/

 

[CHJ]

.....does that sound ok?

Not really IMO.

.....i will make the body of the tool with nothing-special-steel

Made to small enough dimensions to accommodate those tips, the steel used is going to have to be better than "nothing-special-steel"

..... and i will tip it with these tips maybe?
http://cgi.ebay.co.uk/SPARE-TIPS-INDEXA ... 3a51f60951

Not what I would consider for hollowing, at worst you will have a thread like vee cut, at best you will have sharp edged 9mm wide flats dependant on how you locate the insert, both of which will be difficult to blend, far better to get round inserts.

 

[SVB]

I had throught about this and dismissed it as the geometry of tips for metal cutting and wood cutting are radically different therefore I assumed torn grain and plenty of it would be the outcome.

Comparing a rollly or hunter carbide cutter with any metal cutting carbide tip shows great difference with the timber application having a sharp edge (20 deg ish) and the metal application near 70 deg.

Perhaps for a long life scraper but not sure worth the effort for that?

Therefore I did not follow this any further.

Just my thoughts,
Simon

 

[jasonB]

Could be OK...

Depending on how you make the holder it could be out of any metal you had, if you look at the scraper in the pic I linked to earlier you will see that the end of the shank has been reduced in dia, this keeps the shank stiff but gives clearance below the tip. The other alternative is to machine a recess into the end of the shank to take the tip, this way you could easily mount them on a 12mm or larger shank but would loose the ability to mount the tip at different angles

The triangular ones will remove wood quickly but will not be ideal for smooth contors, if you look at the specs for the tips the 2nd pair numbers after the letters signify the tip radius, higher the number greater the radius though a triangle will always be a bit coarse. The only thing it will give a smooth finish on would be say the straight side of a box if one edge of the triangle were set almost along the lathe axis.

A better choice would be a round tip, these are on e-bay search for RCMT or RNMG with a the first two digits of 12, 15, 18 these would be 12, 15 or 18mm dia.

The other thing to watch with these swan neck tools is they wand top rotate downwards with the cutting load, thats why the one you show has a square or rectangular shank.
J

 

[CHJ]

These tips will cut far better than metal working inserts.

Ci0 Accessories For the Ci0: Ci0 Round Carbide Cutter

There is a penalty though, $17.99 ea

 

[mike s]

i cant find any round tips for the money i want to pay (im a tight git)
i guess i will just have to pay out and take a risk making a tool that might not work out

for the shank of the tool i have two ideas

1) use 6mm thick 1" wide mild steel
- easy to work but not very strong

2) an old high carbon steel 1" sorby skew that wont hold an edge long enough to turn with
- hard to work but stronger

i think the mild steel would vibrate quite a bit.... but then the high carbon steel might too

 

[mike s]

is it possible to grind carbide?
you say the angle of the metalworking tips is not right, maybe i could regrind it to the desired angle?

it could be worth the effort if i save £10

 

[CHJ]

is it possible to grind carbide?
....

Yes if you have a Grinder fitted with a Green Grit grinding wheel, I personally have not managed to get a sharp enough edge for wood cutting on a metal cutting carbide tool.

The Ci1 tips I have, I clean up with a diamond card.

 

[mike s]

ok i will scrap this idea
i will wait until i get enough pocket money to buy a proper hollowing tool

thanks for the help and warnings

 

[CHJ]

Mike, why don't you have a go at making an Oland Tool.
You can use 3/16" square or round HSS stock for cutter.

 

[mike s]

thats the second tool i was going to make
heres the plan, i hope it sounds right to you more experienced craftmen
get an old blunt hss drill bit (im choosing 9mm because thats the only one thats blunt)
i will cut the shank off it (the round bit at the top with no flutes that the chuck holds, not sure if its called the shank or not)
thats about 1 1/4" long for me. thats my hss cutter
drill a hole in a mild steel straight or at an angle
tap a set screw to hold the cutter in
make a handle for it
sharpen the cutter like a scraper
about 24" total length
tool done

i could even find a way to bend the bar into a swan neck shape and make that into a hollowing tool...?

sound right?

 

[NetBlindPaul]

mike s,
You will find the shank of a twist drill is not as hard as the flute area it is more tough than hard as it is not designed to cut.

 

[mike s]

:/ poo

 

[CHJ]

Mike, somewhere on the net is an oland tool bit made out of the front end of a small HSS twist drill. The secret is in the way the cutting flute and web backing is ground to form a very effective cutting tool without undue grab.

 

[NetBlindPaul]

Better shout CHJ I think.
The flute area will be nice and hard and will even have some read made clearance angles in it for you.

By the way IIRC there was a question earlier in the thread about grinding tungsten carbide tips.
A silicon carbide wheel as suggested, this is a very rough solution, not rough as in a bodge but rough as in coarse.
A better wheel would be one of cubic boron nitride cbn it is the material used to grind tct saw tips.
VERY expensive, but VERY long lasting.

 

[mike s]

chas, do you mean something like this? http://www.youtube.com/watch?v=TyN-RZOPB4M

and thanks for the info paul